1. Field of the Invention
The field of the present invention is keyboards for use with computers, word processors, electric typewriters and the like.
2. Description of the Prior Art
The well known keyboard design that has generally been used for typewriters and computers has four parallel rows of keys. Each row is adjacent to another row, and the rows are located one on top of the other. The top row of keys is numeric, and the bottom three are alphabetical.
Alphanumeric indicia on the keys of the standard keyboard are arranged in a QWERTY design. "QWERTY" stands for the six letters running from left to right in the top row of alphabetical keys.
The keys in each of the four rows are slightly staggered to shorten the distance the finger must travel between keys in adjacent rows. Minimizing the distance the fingers must travel is important because decreased typing speeds and increased error rates result as the distance a finger must travel from its normal, or "home," position increases. Furthermore, longer strokes increase muscle strain and fatigue.
The parallel arrangement of straight rows of keys used in the typical keyboard design requires the hands to be held in a relatively unnatural position. Users must hold their wrists close together and turn their hands outward. Furthermore, elbows are generally pressed against the body. This position forces users to strain muscles from the shoulders to the fingertips in order to keep wrists horizontal to the keyboard and reach all the keys, causing fatigue and strain. To make matters worse, many typists, working at computer stations, position their hands over the keyboard with the sensitive wrist cocked upward or downward, compressing the tendons, ligaments and nerves that run through the narrow confines of the wrist.
Frequent users of standard keyboards are often afflicted with a serious repetitive stress injury (RSI) known as carpal tunnel syndrome. This disease is the long term result of irritation and inflammation of the median nerve and is caused by maintaining the fingers, hands, wrists, and arms in the unnatural position required to use the standard QWERTY keyboard. Carpal tunnel syndrome and other related RSI injuries have resulted in lost productivity, rising insurance and worker's compensation claims, and, more recently, a rise in product liability suits against keyboard manufacturers.
There have been attempts to redesign keyboards to allow users to assume more natural wrist and hand positions while typing. One such approach has been to bend the rows of keys in the middle to form a V-shaped arrangement. This arrangement is less fatiguing because it allows operators to turn their wrists outward somewhat so that their hands are held more directly in line with their forearms.
A problem with existing V-shaped, or "chevron", keyboards is that most of them do not use the standard QWERTY key arrangement. Therefore, existing chevron arrangements must be relearned by a typist whose only prior training and experience is usually on QWERTY keyboards. Furthermore, many chevron keyboards have such large gaps between the keys on alternate sides of the keyboard that they cannot be readily modified for use by a QWERTY trained typist. Also, chevron keyboards are not generally suitable when it is desired to minimize the typing area, for example, a laptop, notebook or pocket computer. And while the chevron design permits the wrists to be held in a more natural position, the elbows are still generally maintained close to the body because of the geometry of the keyboard. Thus, the upper portion of the arm and shoulders remain in a strained position.
Another general problem with V-Shaped boards of the prior art is that they fail to prevent users from cocking their wrists upwardly or downwardly while typing. Thus, even with V-shaped or chevron shaped keyboards the tendons, ligaments and nerves that run through the narrow confines of the wrist can continue to be compressed and cause the operator to suffer RSI.
Chevron boards that have attempted to use the standard QWERTY key arrangement have not been entirely successful. The shape of the keys in the center section of the keyboard must be altered in specific ways to accommodate the chevron pattern and to provide an interlocking arrangement between the rows of keys at the center, where the angle is formed. Namely, the base perimeters of three keys (the U key, the B key, and the space bar) must be formed into chevrons, and the base perimeter of four keys (the 6 key, the 7 key, the G key, and the H key) must be formed into irregular trapezoids. Increased complexity in the key shapes causes a corresponding increase in the set up costs for manufacturing the key board. Also, the angle of finger throw in these keyboards is different than that of a standard QWERTY a keyboard, and no symmetry exists in the amount the keys are staggered on each side of the keyboard center. Thus, QWERTY-trained operators will experience increased error rates until they gain complete tactile familiarity with the shifted keys.
Therefore, a need exist for an improved ergonomic keyboard that maintains the wrists and elbows in a more natural position and that may be picked up by a QWERTY trained typist without having to change their typing style or the angle of their finger throw when striking keys in adjacent rows.